Fix misplaced transaction
Fix misplaced transaction

PR #180 moved 2 of the 3 transaction begin/commits from
the Superqueue to PgsqlAdapter, but the bufferJob()
transaction was eliminated and the markJobAsQueued()
transaction was duplicated.  This PR removes the duplicate
transaction from markJobAsQueued() and adds a transaction
to bufferJob().

lightster/hodor,Twenty7/hodor,lightster/hodor